Cannes launches first roadside nitrous oxide testing in France

Cannes has become the first French city to implement roadside testing for nitrous oxide (N2O). Since August 20, 2026, the municipal police have been using three detection devices to monitor drivers suspected of inhaling the gas, particularly after traffic violations are observed.

The technology, known as OCIN2O, was developed by the Aix-en-Provence-based startup Olythe. It utilizes miniaturized non-dispersive infrared (NDIR) spectroscopy to analyze exhaled air. According to co-founder Guillaume Nesa, the device provides immediate concentration results after a breath test lasting only three to four seconds, offering a rapid alternative to traditional biological analyses.

This local initiative by Mayor David Lisnard precedes the national Ripost law, which mandates a general ban on the sale of nitrous oxide starting February 1, 2027. The city's move follows previous efforts to restrict the gas, including a 2025 municipal decree that expanded prohibitions to all individuals.